Overview
- The Adelaide University team, whose results were published Thursday in Communications Biology, found human, mouse and pig sperm struggled to find their way through a tract-like maze when gravity cues were removed.
- They simulated weightlessness with a 3D clinostat that constantly rotates samples and used a channel modeled on the female reproductive tract, showing navigation dropped even though swimming ability did not change.
- In mouse tests, about 30% fewer eggs were fertilized after four hours in the simulator, and longer exposure led to early developmental delays and fewer embryo cells that form the fetus.
- Adding progesterone, a hormone released by the egg, improved human sperm navigation under simulated microgravity, suggesting chemical signals can partly offset the loss of gravitational guidance.
- Because the clinostat is a ground-based simulation rather than true microgravity, the authors plan graded-gravity studies for Moon and Mars levels and tests of artificial gravity, noting that many embryos still formed despite the impairments.